Various types of ventilation apparatus are known for use in passenger aircraft. One very common type of ventilation apparatus is coupled to the aircraft pressurization and air conditioning system and comprises a central pressurized air distribution unit having a plurality of outlets each corresponding to a passenger position within the aircraft. A ball and socket valve type outlet is provided adjacent each passenger position and comprises a socket in which is seated a ball type outlet nozzle, the nozzle having a permitted range of movements in three dimensions. Threadably mounted on the nozzle is a sleeve whose orientation relative to the nozzle's stem determines the amount of flow of pressurized air passing through the nozzle.